Author Topic: Noise from waste pipe  (Read 3871 times)

J. Hall

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Noise from waste pipe
« on: January 26, 2003, 08:24:03 AM »
I have a waste pipe from an upstairs bathroom that runs inside one of the walls of my bedroom. When someone takes a shower or flushes the toilet upstairs it sounds like Niagra Falls inside the wall. What combination of things can I use to dampen this sound? I say combination because no way is one thing taking care of this. Is there something I can wrap the pipe with then something to put around that to fill the rest of the wall and even some sheet of something to put over the whole thing before putting the drywall back?



Bill Wallenfels

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Re: Noise from waste pipe
« Reply #1 on: January 30, 2003, 02:40:17 AM »
: I have a waste pipe from an upstairs bathroom that runs inside one of the walls of my bedroom. When someone takes a shower or flushes the toilet upstairs it sounds like Niagra Falls inside the wall. What combination of things can I use to dampen this sound? I say combination because no way is one thing taking care of this. Is there something I can wrap the pipe with then something to put around that to fill the rest of the wall and even some sheet of something to put over the whole thing before putting the drywall back?
I had the same problem.  Usually (as was my case) you don't have much room to work with in the wall.  I removed a vertical strip of drywall completely from the wall on the other side of the bedroom wall and mounted a decorative 6 in wide wood strip to cover the opening.  This gave the thickness of drywall to work with and allowed the pipe to move a little from the bedroom wall.  Also there was a romex wire pressing the 3.5 inch pipe against both drywalls. The enlarged opening allowed this to not contact the pipe. This solution lowered the noise noticeably (guess = 10 dB) but I can still hear the rush:  I wrapped the pipe with 1/32 lead foil.  It molds easily and contact cement holds it nicely.  I wedeged 1/4 Foam Mat at top and bottom to try to isolate the pipe from joists at the ceiling and floor. Then I wrapped the lead covered pipe with 1/8 inch Foam Mat again using contact cement. I stuffed a double thickness of 1.5 inch Foam Mat on either side, but I doubt it had much effect.  I suspect most of my noise now is from the ceiling and floor penetrations, which are difficult to enlarge and treat.


Ed Brown

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Re: Noise from waste pipe
« Reply #2 on: February 14, 2003, 10:17:41 PM »
This might sound a little drastic, but as long as you're tearing off the drywall, you might consider replacing the riser pipe with cast iron (assuming that it is plastic now). Believe it or not, many building codes, at least for multi-family housing, require these cast iron riser pipes to address the very problem you're having (which is even more annoying if it's you neighbor flushing and not a member of your family).
The job can be done with two "no-hub band" couplings, the biggest challenge being how to get the cast iron pipe cut to length.
Anyway, this is just a thought . . .